Annell Aqueduct (lower section)

Cadw's description

Summary description and reason for designation

The following provides a general description of the Scheduled Ancient Monument.

The monument consists of the remains of part of a water channel, known as the Annell Aqueduct, dating to the Roman period. It is believed to have been constructed in conjunction with the Roman exploitation of the gold mines at Dolaucothi, probably in the later 1st and early 2nd centuries AD. The multiple channels on this stretch are thought to represent an effort to overcome a particularly steep drop; above and below this stretch there is no sign of more than one channel. Its source was originally presumed to be near SN 707 436, on the upper reaches of the Annell, the valley of which it is assumed to follow, hugging the contour of the hillside, towards Caio, swinging westwards from there towards the main mine area. A similar portion to this, higher up this course, is scheduled as CM211. More recent work has suggested that the aqueduct may have extended further to the north-east, to tap the headwaters of the Gwenlais, which otherwise flows south-east towards Cilycwm. Parts of its course were probably carried on or supported by timber structures which do not survive. This is part of a network of leats serving the Dolaucothi mine, and an important demonstration of the sophistication of water management by Roman engineers.

On this stretch, one main channel runs the entire length, starting at the north end with an apparently steep drop from a boggy area. After about 75m, when this levels out, it is joined by a second line below it. About 375m further on, the aqueduct passes a strong spring and to the south of this three channels are visible, the lowest channel appearing to start at the spring. This triple stretch is very clear and well preserved, although unfortunately the remains cannot be traced beyond the next field boundary.

The monument is of national importance for its potential to enhance our knowledge of Roman structural engineering and mining technology. The scheduled sections of the monument are generally well-preserved and an important relic of their Roman construction. They retain significant archaeological potential, with a strong probability of the presence of both structural evidence and intact associated deposits.

The scheduled area comprises the remains described and areas around them within which related evidence may be expected to survive. It consists of an area up to 35m wide by 320m long.